code: def test_parallel(app):
      app.build()
      index = load_searchindex(app.outdir / "searchindex.js")
      assert index["docnames"] == ["index", "nosearch", "tocitem"]
  
imports: import json
  import warnings
  from io import BytesIO
  import pytest
  from docutils import frontend, utils
  from docutils.parsers import rst
  from sphinx.search import IndexBuilder
label_desc: Use image node_id 15 for calling a global function with example usage: test_parallel(app) without return types